The present invention relates to a coolant tube of a heat exchanger; and, more particularly, to a method and an apparatus for manufacturing coolant tube capable of improving the efficiency of a heat exchanging performance of a heat exchanger which is widely used as, e.g., a radiator of air conditioners.
In general, a heat exchanger of a capacitor used as a radiator of air conditioners includes header pipes made of aluminum. The header pipes have a plurality of coolant tubes through which coolant flows. Heat exchange is performed between the coolant and an air flow while the coolant circulates through the coolant tubes.
Referring to FIG. 1, there is provided a conventional coolant tube 101. The coolant tube 101 is fabricated through an extrusion molding process via an extruding device such that a plurality of coolant circulation passages 102 is formed inside of the coolant tube 101. Alternatively, as shown in FIG. 2, a plurality of coolant circulation passages 104 can also be formed by installing inner fins 103 within a coolant tube 101 prepared by the extruding device.
However, such conventional coolant tube manufacturing methods exhibit certain drawbacks. First, since an extruding process for forming the coolant circulation passages 102 is sophisticated or a die for forming the inner fins 103 can not be readily manufactured, there exists a great deal of difficulty in fabricating the coolant tube. Further, coolant tubes 101 with an inadequate thickness and coolant circulation passages 102 with an improper shape are frequently produced in case where an extruding operation of the extruding device is not properly maintained. Still further, since the coolant circulation passages 102 formed in the coolant tube 101 are completely separated from each other, the coolant traveling through the coolant passages is forced to flow in one direction and a heat exchanging area of the coolant is inevitably limited. Consequently, the efficiency of the heat exchanger is greatly deteriorated.
It is, therefore, an object of the present invention to provide a method for fabricating a coolant tube capable of improving the efficiency of a heat exchanger.
It is another object of the present invention to provide an apparatus for manufacturing a coolant tube capable of improving the efficiency of a heat exchanger.
In accordance with one aspect of the present invention, there is provided a method for manufacturing a coolant tube of a heat exchanger by using a plate member, comprising the steps of: forming a plurality of folded portions on the plate member by folding the plate member in substantially regular distances; and joining opposite ends of the plate member in a manner that end parts of the folded portions are brought into contact with flat portions of the plate member to form coolant flow passages.
In accordance with another aspect of the present invention, there is provided an apparatus for manufacturing a coolant tube of a heat exchanger by using a plate member, comprising a roll including: a plurality of formation grooves for forming a plurality of folded portions on the plate member; and a roll having a plurality of flow groove formation units for forming flow grooves on the plurality of folded portions formed on the plate member, whereby the plurality of folded portions having the flow grooves are formed on the plate member when the plate member passes through the roll.
In accordance with still another aspect of the present invention, there is provided an apparatus for manufacturing a coolant tube of a heat exchanger by using a plate member, comprising: a rolling device for forming a plurality of folded portions on the plate member; and a die press having a plurality of protrusions formed at the bottom thereof so as to form flow grooves on an upper part of the folded portions.